Whenever this creature blocks or becomes blocked by a creature, change this creature's base power and toughness to that creature's power and toughness until end of turn.

This creature has flying as long as you control another Merfolk.

, : Target creature gains first strike until end of turn.
, : Target creature gets +1/+0 until end of turn.

Morph
When this creature is turned face up, target creature gets +2/-2 or -2/+2 until end of turn.

Changeling
: Target Shapeshifter becomes a copy of target creature until your next turn.

Whenever Shellfish Scholar or another Rat you control enters, conjure a card named Think Twice into your graveyard.
Threshold — : Spells you cast from your graveyard this turn cost less to cast. Activate only if seven or more cards are in your graveyard.

Flying
, : Return another target permanent you control to its owner's hand. Activate only during your turn.

When this creature enters, put a shield counter on target noncommander creature you don't control. You gain control of that creature for as long as it has a shield counter on it.

Flash
Whenever this creature blocks, you get .
, Pay : Draw a card.

Slivers can't be blocked except by Slivers.

, Exile this creature: You may put a creature card from your hand onto the battlefield. If you do, that creature gains haste until end of turn. At the beginning of the next end step, sacrifice that creature. If you do, return this card to the battlefield.

Flying
As long as you control four or more artifacts, this creature has hexproof.
Tap two untapped artifacts you control: Draw a card.

Flying
Phasing
Whenever this creature phases in, target creature phases out.

Flying
Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability.

Flying
Cycling

Flying
Channel — , Discard this card: Target creature gains flying until end of turn.

Flying
Vivid — When this creature enters, draw cards equal to the number of colors among permanents you control.

: Monstrosity 4.
When this creature becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control this creature.

Prowess
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Raid — When this creature enters, if you attacked this turn, you may draw a card. If you do, discard a card.

When this creature enters, you get .
Pay : This creature gets +2/-2 until end of turn.

When this creature enters, tap target creature an opponent controls and put a stun counter on it.

Defender
As long as an artifact entered the battlefield under your control this turn, this creature can attack as though it didn't have defender.

When this creature enters, draw a card, then discard a card.
Whenever you discard a Spirit card or a card with disturb, put a +1/+1 counter on this creature.

Constellation — Whenever an enchantment you control enters, you may draw a card. If you do, discard a card.

Defender
Landfall — Whenever a land you control enters, this creature loses defender until end of turn.

, , Sacrifice this creature: Draw three cards.

: Exile this creature, then return it to the battlefield face down under its owner's control.
: This creature gets +1/-1 or -1/+1 until end of turn.
Megamorph

This creature can't be blocked.
Threshold — Whenever this creature deals combat damage to a player, draw a card. Then discard a card unless there are seven or more cards in your graveyard.